The Foo Fighters made the most of their headlining appearance at Firefly Music Festival in Dover, Delaware on Friday night, delivering their only performance on the books so far this summer for a crowd of 80,000 fans.

After running through an initial 16-song set packed with classics including "This is a Call," "Times Like These" and "Monkey Wrench," the band returned for a string of covers, beginning on a seasonal note with Alice Cooper's "School's Out" before hitting the Rolling Stones' "Miss You," Van Halen's "Ain't Talkin' 'Bout Love," and Queen and David Bowie's "Under Pressure." "We’re gonna do something we’ve never done before," Grohl said as he introduced the covers, according to MTV. "For the next 20 minutes, we’re a bar band called the Holy Shits that plays classic rock songs."

As Billboard reports, guitarist Chris Shiflett played the entire Firefly show sitting in an office chair, which Dave Grohl explained as necessitated by an injury. "Chris broke his foot, or his ankle or something, but he came out here to play for you guys anyway," he said. "You know how you did it? By being fucking old."